The present invention relates to improvements in apparatus for manipulating sections of flexible webs or the like, especially for stacking sections of exposed and developed photograhic customer films. More particularly, the invention relates to improvements in apparatus for accumulating successively delivered sections of photographic customer films or the like in a receptacle wherein the successively delivered sections overlie each other.
It is already known to stack photographic prints in an apparatus wherein successive prints are deposited on the wings of two rotating paddle wheels. When a print comes to rest on two registering wings, the paddle wheels are caused to rotate in opposite directions and thus to deposit the print onto a platform. At the same time, the next-following wings of the paddle wheels are moved to optimum positions for reception of the next-following print. The just described stacking apparatus is normally installed immediately downstream of a severing device which subdivides a series of coherent paper prints into discrete prints. The stacked prints are thereupon inserted into envelopes and returned or shipped to or picked up by dealers or customers. The foremost print which issues from the severing device is caused to automatically advance onto the two registering wings of the paddle wheels, and the severing device or a detector thereupon transmits a signal which causes the paddle wheels to turn, normally through 90 degrees, so as to deposit the foremost print onto the growing stack. A drawback of the just described stacking apparatus is that, even though it can rapidly assemble a stack of paper prints, it is less suited for the stacking of sections of photographic films because the films normally exhibit a strong tendency to curl. Moreover, the tendency to curl often varies from film to film, so that the apparatus may be capable of properly stacking sections of a first film but cannot perform the same function in connection with the next-following film or films. If the tendency of a film to curl is very pronounced, the sections on the wings of the paddle wheels tend to bulge upwardly and prevent rotation of the paddle wheels in directions to deposit the film section thereon in the receptacle therebelow. Moreover, the strips which are already stacked on top of each other are likely to prevent the deposition of an oncoming strip, so that such oncoming strip can be deformed or even destroyed. Apparatus of the just described character are disclosed in the commonly owned German Offenlegungsschrift No. 2,614,038 and in the corresponding U.S. patent application Ser. No. 906,606 filed by Bruno Regele on May 16, 1978.
An apparatus which serves to stack sections of photographic films is disclosed in German Offenlegungsschrift No. 2,553,612.3. In this apparatus, the strips are introduced into discrete compartments of a gathering device. All strips which belong to a given customer order are expelled from their compartments in a single step and are advanced toward or directly inserted into an envelope or another suitable receptacle. Such apparatus are quite satisfactory for manipulation of film sections; however, the controls which regulate the admission of sections into the compartments and the expulsion of stacked sections from the compartments are rather complex and expensive. A similar apparatus is described and shown in commonly owned U.S. Pat. No. 4,154,046 granted to Klaus Weber et al. on May 15, 1979.